Synthetic-jewel bearing



x 15 ject to of materials, but it is fundamentall J I j? G. KODOUGAL AND SE12 5:3. MQDOELL, FLINT, MICHIGAN, ASSIGNORS T F1033 IGNITION COMPANY, OF FLINT, MICHTGAN, A CORPORATIUN 0F MICE- r HETIC-JEL rename.

Ito Drawing. Original application filed January it, 1820, Serial No.,851,438. I Divided and this application filed February 10, 1922. I Serial anteater.

To all it my concern: Be it known that .we TAINE G, McDonoan and SAMUEL J. Mobownnn, citizens of the Uni d States, and residents of\ Flint,

county of Genesee, and State of. Michi n,

have invented certain new and useful mprovements in Synthetic-Jewel Bearmgs of which the following is afull, cleari COIlClSB,

and exact description; such aswil enable others skilled in the art to which the invention relates to make and use the same. 7 The present invention relates to ewel bearings such as are adapted for use. in speedometers and other instruments, the obbeing both to improve the quality of the bearing and to materially reduce its cost, In other Words, the invention is concerned with a process of manufacture as well as with the bearing itself. Claims on the process of manufacture are embodied in our ap lication for United States Patent Serial, 0. 351,438, filed January 1f 1920,

' now Patent No, 1,422,216 of which the present application is a division; but it is deemed advisable, in order that the invention as a whole may be best understood, to describe in the present application both the article and the several steps with which its manufacture, as involved in the preferred practice, may be divided.

1st. The formation of a glass of a highly viscous nature when fused which serves as the base from which the bearings are made and which allows a better control of the shrinkage (that results from subsequent treatment) than could otherwise be obtained with the rawingredient or ingredients comosing the glass batch This glass may be ormed of various materials or combinations 1mortant to the success of the process t at it Be very viscous when fused, since a bearing of such material will retain its shape during the'burning or hardening process and will as moreover present a smooth surface such as avoids any necessity for polishing subseuently to the heat treating operation. anifestl this glass should also be of a very har nature when cooled to normal to temperature. One form of such glass may be made from raw pulverized felds ar (mined as a crystalline rock and groan to pass a screen of say one hundred meshes to the inchl'as it is commonly prepared for the pottery trade, but it is desirable to add .dextrin or other suitable binding material rather coarse screen say sixty meshes to the inch) while in 't is damp condition. This step. is the first onethat would be necessary should raw feldspar, as ground for the pottery trade, be used.

4th. The granulated material is then dried and preferably screened to remove all particles too large or too small, as, for example, by being passed through a screen of sixty meshes per inch and also through a screen of one hundred fifty meshes per and is then preferablgl rubbed through a inchso that the material finally retained is of a quite uniform size and small enough to permit free flow. into the dies or ress.

5th. The dry granulated material thus formed is then fed into suitable hardened dies whereby it is compressed and proper- 1y shaped; and in order to reduce the wear on the dies, a small amount of kerosene or the like is preferably mixed with the powder for lubricating purposes.

6th. After being discharged or removed from the press, the shapes or pellets, which are ordinarily of ring formation, are then received or placed in refractory trays, the bottoms of which are covered with a layer of finel divided powder of some material, prefera 1y aluminum oxide, which forms a bed therefor and which will notadhere to the jewels or chemically combine therewith during the firing or fusing process, The

jewels are thus free to shrink and do not become fused with the powder or attached thereto.

7th. The shapes are next heated to cause fusion, said treatment being arrested at a point such as to give the size desired and to insure thefinish or polish necessary to insure a bearing withflminimum trictlon. this operation the materialis heated sutliciently tocause what is technically called fusion but not suiiiciently to cause formation, the actual temperature being dependent somewhat on the particular material used, and being determined by two considerations, namely, the formation of a satisfactory fused surface, and, second, the retention of the shape to which the pellet or ring was originally compressed. lit the heating is too low,

the surface will be rough, and if the heating is too high the bearing will be deformed.

The bearings are then annealed or slowly V cooled.

When it is desired to imitate natural jewel bearings, a suihcient amount ofcoloring matter -is introduced into the mixture from which the glass is originally made, or to the granulated material.

As a modification of the process lieretofore outlined, it is preferred in some instances to form the constituent material or base in two separate batches, one of I which has a less'tendency to deform than the other,that is, is more viscous when heated to the same temperature, for example, one batch may be of the felkds ar-clay glass heretofore fired or baked the thin veneer of the second material fuses more readily than the body, I

readies thus resultin smoother surface after heat treatment as previously described. The body remaining more rigid on account of its greater viscositv or higher tusibility or deformation point, lends stability to the whole pellet.-

The invention further comprises the production of bearings as heretofore described whether or not formed from premelted lass,

that is, they may be formed froma non- "used pressed and heat-treated (without pre-melting) inthe manner'outlined. above, but the resultant articles are more subject to shrinkage and otherwise less desirable than when formed in the preferred manner heretofore stated.-

We claim:

powdered ass, essentially of high viscosity when fuseg, compressed into a pallet and subseguently fused and annealed.

2. ringshaped bearing shaped by compression of powdered material, capable of forming a glass of high viscosity when hot and hardness when cool, and subsequently,

fused without material distortion from the shape imparted by said compression.

rrliaterial formed of a mixture of feldspar and e W d. An annular bearing of fused ceramic material in which feldspar is used to the extent of substantially sixty percentor more ltn testimony whereof we ailix our-signatures. TAINE G. MoDtlUGAL.

SAMUEL J, MODQWELL in a facing is-lietter glazed than t e body and which presents a base or substantially the same raw material ,or materials, screened, granulated, com-= 1. A. jewel bearing or the like formed from.-

3. An annular bearing of fused ceramic 

